PESHAWAR, Pakistan - A suicide bomber demolished a mosque packed with hundreds of worshippers attending Friday prayers near the Afghan border, killing at least 48 people and injuring scores more, in the bloodiest attack in Pakistan this year.
The bomber struck at the climax of the service, as the mosque leader was starting the communal prayer, witnesses said.
"As the prayer leader said 'God is Great', the bomb went off with a big bang," said Nadir Shah, a local paramilitary solider attending the mosque. "I felt it was the end of everything. Sometime later when I opened my eyes, I was lying among dead bodies."
The blast in the fabled Khyber Pass came hours before President Barack Obama unveiled a revised strategy to "disrupt, defeat and dismantle" the al Qaeda terrorist organization and the Taliban operating in Afghanistan and Pakistan's northwest.
A government official accused Islamist militants of carrying out the bombing in revenge for a recent offensive aimed in part at protecting the major supply route for NATO and U.S. troops in Afghanistan that passes in front of the mosque. Several of the dead were local security officers who were praying there, officials said.
"Residents of this area had cooperated and helped us a lot. These infidels had warned that they will take revenge," said Tariq Hayat, the top administrator of the Khyber tribal region. "They are the enemy of Pakistan. They are the enemy of Islam."
Rising violence in Pakistan is fueling doubts about the pro-Western government's ability to counter Taliban and al Qaeda militants also blamed for attacks on Western troops in Afghanistan.
The bomber hit the mosque, a popular stop for travelers motoring between Pakistan and Afghanistan, when about 250 people were attending Friday prayers, said Hayat.
Television footage showed scores of residents and police officers digging frantically with their hands through the ruins of the white-walled mosque, whose roof collapsed in the explosion.
Rescuers hauled bodies covered in dust and blood on blankets and scarves toward ambulances and private cars waiting to take them to hospital. Crowds of anguished women waited in the background, hoping for news of loved-ones.
Hayat said rescuers had pulled 48 bodies from the rubble and predicted the toll would likely rise further. Another 80 people were injured, he said. Several police officers who had been manning a nearby checkpoint were reportedly among the victims.
The mosque in a rocky valley near the town of Jamrud lies on the main road along which trucks carry vital supplies to the expanding U.S.-led force in Afghanistan.
Suspected Taliban militants have carried out a string of attacks on both trucks and transport depots along the route in recent months, destroying scores of military vehicles, including Humvees, and raising doubts about the reliability of the supply line.
The area has also been beset by feuds between rival tribal and militant groups -- some loosely allied with the government, others close to the Taliban -- which have included suicide bombings and attacks on mosques, though none so deadly as Friday's blast.
Frustrated at Pakistan's failure to gain control of the border belt, the U.S. has carried out an intense campaign of missile strikes into the region since last year.
President Asif Ali Zardari on Friday reiterated Pakistan's opposition to the strikes, apparently carried out by unmanned CIA aircraft. The government says the attacks feed anti-American feeling and undermine its own effort to isolate extremists.
"We hope Obama is a name for change," Zardari told reporters in the southwestern province of Baluchistan, a region that some have speculated will be the next target of the drone attacks.
Zardari also urged Obama to take a "regional approach" as part of his new strategy for tackling extremism and terrorism, a change Pakistani officials hope would leave them shouldering less of the blame for the Taliban's resurgence.
The Afghan intelligence chief on Thursday accused Pakistan's powerful military spy service of secretly aiding the militants_ a charge vehemently denied in Islamabad.
Weary of rising violence inside their own borders, Pakistani authorities have struck peace deals in some Taliban-dominated areas, an approach Western officials complain lets militants step up the war in Afghanistan.
Three key Taliban commanders in Pakistan recently announced a new alliance to fight "infidels" led by "Obama, Zardari and (Afghan President Hamid) Karzai."
The commanders -- Hafiz Gul Bahadur, Baitullah Mehsud and Maulvi Nazir -- are based in the North and South Waziristan regions, the main focus of the U.S. missile strikes. The three are divided on tribal lines and have feuded in the past.
Their statement last month didn't say where the Ittehad-ul-Mujahideen, or Union of Holy Warriors, would focus its efforts.